In a cellular wireless communication system, terminals located in a cell boundary are limited in increasing a data transmission rate due to large interference from other cells. Multi-cell coordinated communication, a technique for increasing a data transmission rate of terminals located in a cell boundary, is one of candidate techniques to be applied to a 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE)-Advanced system. The multi-cell coordinated communication for an Orthogonal Frequency-Division Multiple Access (OFDMA) downlink which is being discussed for the LTE-Advanced system can be divided into the following two fields:
Joint transmission (joint processing): a terminal receives data from a plurality of transmission points; and
Coordinated scheduling: a terminal receives data from one transmission point. Scheduling, precoding or beam forming of a terminal is performed through coordination (or cooperation) of multiple cells.
In most cases, one cell usually has one transmission point.
In a conventional multi-cell coordinated transmission method, only a serving cell receives channel state information (CSI) transmitted from a terminal via the uplink, information necessary for cooperation is extracted from the CSI, and the extracted information is transmitted to a surrounding coordinating cell. However, if the serving cell and the coordinating cell belong to different base stations, there is a problem in that information exchange between the cells causes a transmission delay and a traffic increment of a backhaul network.
As a conventional multi-cell coordinated communication method, U.S. Pat. No. 7,428,268, entitled “Cooperative MIMO in multicell wireless networks”, discloses a joint transmission operation under a structure in which the serving cell and the coordinating cell belong to different base stations. In U.S. Pat. No. 7,428,268, a method in which a base station of the serving cell and a base station of the coordinating cell perform joint transmission is described. However, as described above, if the serving cell and the coordinating cell belong to different base stations, there is still a problem in that the transmission delay and the traffic overhead of the backhaul network are caused at the time of information exchange between the cells.